Jack Kerouac's On the Road is an American classic, but the trailer for Walter Salles' film adaptation is, well, something else. Sam Riley, Kristen Stewart, Garret Hedlund, Amy Adams, Kirsten Dunst and Viggo Mortensen all star in the slick big-screen version, and the lively look in Stewart's eyes – and the amount of skin on display – are unusual for the Twilight actress. On the Road opens December 21st.